The statements in this section merely provide background information with relation to the present disclosure and may not constitute the prior art.
H.264/AVC is a standard for video codec with the best compression rate among the present standardized video CODECs. In the H.264/AVC standard, a video is predictably encoded using directional intra prediction, integer transform by 4×4 pixel, block mode with various sizes from 16×16 pixel block to 4×4 pixel block, deblocking filter, and the like in order to increase compression efficiency.
In High Efficiency Video Coding (HEVC), which is recently being standardized, intra predictions are carried out on blocks of sizes 4×4 to 16×16 and beyond in order to attain more efficient results than H.264/AVC. As shown in FIG. 1, the intra prediction can be performed in consideration of the maximum of thirty-four directions to predict a current block ever more precisely.
The known intra prediction methods perform a unidirectional prediction. The inventor(s) has, however, noted that where the current block has a significantly small size or only one feature, using information on a plurality of neighboring (or surrounding) pixels might increase the efficiency of predicting the current block. The inventor(s) has, however, experienced that in the known intra prediction, since only a simple unidirectional prediction is used, an improvement of an encoding efficiency is limited.